Recently, in the semiconductor industry supporting rapidly-developing IT technologies, there has been a demand for the higher integration or better performance of an element and, accordingly, in processes for manufacturing a semiconductor as well, there has been a demand for additional improvement in fine processing techniques. Among these processes for manufacturing a semiconductor, etching techniques are one of the important fine processing techniques and, in recent years, among the etching techniques, a plasma etching technique capable of highly efficient fine processing of a large area has become mainstream.
For example, in a process of manufacturing an LSI using a silicon wafer, the plasma etching technique is a technique for forming a fine pattern on a silicon wafer by forming a mask pattern on the silicon wafer using a resist, introducing a reactive gas into a vacuum in a state in which the silicon wafer is supported in the vacuum, applying a high-frequency electric field to the reactive gas so as to cause accelerated electrons to collide with gas molecules which are thus brought into a plasma state, and reacting radicals (free radicals) and ions generated from the plasma with the silicon wafer so as to remove the radicals and the ions as products of the reaction.
In an apparatus for manufacturing a semiconductor such as a plasma etching apparatus, as a device for placing and fixing a silicon wafer onto a specimen stage in a simple manner and maintaining the silicon wafer at a desired temperature, an electrostatic chuck device has been used so far (Patent Literature 1 and 2).
Meanwhile, in the above-described electrostatic chuck device, there are problems of weak resistance to oxygen-based plasma or corrosive gas and a concern of possible damage caused by discharging and the like during the use of the electrostatic chuck device and thus there has been a proposal for an electrostatic chuck device in which an electrostatic adsorption electrode is provided on the lower surface of a ceramic plate-like body, an insulating layer is adhered to the electrostatic adsorption electrode through an organic adhesive layer, and abase plate is adhered to the insulating layer through an organic adhesive layer (Patent Literature 3).
Meanwhile, as an electrostatic chuck device in which the thermal conduction characteristics do not significantly change between the electrostatic chuck device and a plate-like specimen, only a small number of particles are generated, and the attachment of particles to the rear surface of the plate-like specimen can be decreased, there has been a proposal of an electrostatic chuck device in which multiple protrusions are provided on a placement surface on which the plate-like specimen is placed and one or more fine protrusions are provided on the top surfaces of part or all of the protrusions (Patent Literature 4).